1. Field of the Invention
The present invention relates to an optical recording medium and a recording and reproducing apparatus of the same and, more particularly, to an optical recording medium on which data multi-value recording is performed and a recording and reproducing apparatus of the same.
2. Description of the Related Art
Recently, a recording and reproducing apparatus (e.g., an optical disk apparatus) which uses an optical recording medium has begun to be used as a large-capacity data recording apparatus. For example, in this optical recording apparatus, a light beam emitted by a laser optical source arranged above an optical disk as an optical recording medium is focused as incident light by a polarization beam splitter, an objective lens, and the like, and irradiates a track of the optical disk. Light reflected by the optical disk is directed to the polarization beam splitter to be separated from the incident light, and supplied to a photodetector such as a photodiode. An optical signal from the polarization beam splitter is converted by the photodetector into an electrical signal and amplified. Then, data written on the track of the optical disk is read out as recorded data through a sample and hold circuit, a digitizer, a decoder, and the like.
In such an optical disk apparatus, data to be recorded on a track of an optical disk, i.e., recording pits are usually arranged along the track direction in a one-dimensional manner. For this reason, the recording pits are formed at desired intervals. However, this imposes a limit in obtaining higher density data recording.